Alloy steel



Patented June 12, 1934 PATENT OFFICE ALLOY STEEL William H. Keen, Albany, N. Y., assignor to Chris.

- W. Guttzeit, New York, N. Y.

No Drawing. Application June 3, 1930, Serial No. 459,111

1 Claim. (Cl. 75-1) The present invention relates to alloys or eutectic compounds including alloy steels of the type commonly known as high speed steels and has for an objectto provide an improved alloy 5 especially adapted for use in making cutting tools.

The invention has also for an object to provide an improved cutting tool.

I have discovered that the addition of boron causes a marked increase of hardness in a numher of alloy steels to which'it may be added. Its efiect has been studied especially in combination with such elements as nickel, cobalt, tantalum, copper, iron, chromium, tungsten, molybdenum and manganese, with varying degrees of increase in the hardness of the alloy. Ithas been found especially that alloys in which boron is combined with tungsten. give outstanding results especially when used for cutting tools and the like. Alloys in which boron is combined with tantalum have also given effective results with the advantage ofless brittleness. Apparently a compound results I in the form of a boride of one or more of the elements of the alloy treated. Advantage can be taken of this property of hardening in the treatment of many alloys which hitherto have been limited in use due to their lack of hardness.

Boron has been used .by metallurgists heretofore but its function has been considered to be that of a deoxidant and generally when the addition has been made to molten baths it has been in small quantities sufficient only to accomplish the desired deoxidation of the metal.

In accordance with the present invention, the boron is so added that it will combine to effect the composition of the steel, but whether the boron combines in a definite chemical compound or in an eutectic compound has not been deter mined.

As an example, a particularly eflective metal 40 can be obtained by incorporating boron in an such as calcium boride or silicon manganese boride. The resultant metal may be cast to form the tools desired and these tools may be used without heat treatment. In some instances a slow cooling of the tool is desirable to avoid strains in the metal.

' Another method of preparation involves reducing the materials to be alloyed, such as high speed steel scrap, to small size pieces, for example, A, mesh and smallerand then hitting the charge of '65 base metal with the boron or a boride by means of an electric are. This produces small pellets or nodules which can be brazedon to the-cutting nose of a lathe tool. 7

The analysis of illustrative satisfactory steel alloys made in accordance with the invention showed the following compositions- Percent Percent Percent 73 6 50 18 l8 6 2. 5 r and usual impurities The percentage of iron can be very small and good results obtained, in fact boron and tungsten alone can be combined to produce an alloy which can be used effectively for a cutting tool. 5

In the case of steel pellets fritted'with boron or a boride, as above indicated, an ordinary high speed steel containing 18% tungsten, 4% chromium,v and 1% vanadium was found to absorb 2.95% boron.

The foregoing particular description is illustrative merely and is not intended as defining the limits of the invention.

I claim:

A high speed tool steel comprising in combination approximately 18% tungsten, 4% chormium,

1% vanadium and 3% boron in such condition as would result from fritting the steel and boron in an electric arc.

WILLIAM H. KEEN. 00 

